mfd: core: Add locking around 'mfd_of_node_list'

mfd: core: Add locking around 'mfd_of_node_list'

Manipulating a list in the kernel isn't safe without some sort of
mutual exclusion. Add a mutex any time we access / modify
'mfd_of_node_list' to prevent possible crashes.

Cc: stable@vger.kernel.org
Fixes: 466a62d7642f ("mfd: core: Make a best effort attempt to match devices with the correct of_nodes")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20251210113002.1.I6ceaca2cfb7eb25737012b166671f516696be4fd@changeid
Signed-off-by: Lee Jones <lee@kernel.org>